Mechanical key



Jan. 25- v 1,523,635

J. CSIMA MECHANICAL KEY Filed Aug. 15, 1924 WITNESS ATTORNEY ?atented Jan 26,

JULIUS CSIIVIA, OF MILWAUKEE, WISCONSIN.

MECHANICAL Application filed August 15, 1924.

T cZZ 'u izom may concern Be it known that I, JULiUs CsIMa, a citizen of Yugoslavia, residing at Milwaukee, in the county of Milwaukee and State of *isconsin, have invented new and useful Improvements in Mechanical Keys, of which the following is a specification.

My present invention has reference to certain new and useful improvements in keys, and has for its object to provide a key for a door lock with a slidable element in the nature of a pin movable through the bit of the key and designed, when projected, to engage a tumbler in the lock which cannot be engaged by the ordinary lugs on the bit and in this manner render the lock practically burglar proof.

\Vith the above broadly stated object in view and others which will appear as the nature of the invention is better understood, reference is to be had to the drawings which accompanying and which form part of this application.

In the drawings Figure 1 is a side elevation of a key in accordance with this invention, parts being in section.

Figure 2 is a sectional view on the line 22 of Figure 1.

In general appearance, the key is of the ordinary construction, the same including a stem 1. a bow 2 and a bit 3 that is formed on the pin end of the stem. The bit 3 is centrally notched to provide the same with lugs t and 5 respectively. The outer lug 5 has a rectangular bore communicating with a similar bore in the bit and. both of these bores conununicate with the hollow bore 6 of the stem.

Slidable through the lug 5 there is a cross sect-ionally rectangular pin 7. The pin is preferably formed with a notch 8 that receives therein a lug 9 that enters from one side of the bit. In this manner the outward movement of the pin through the bit is limited.

The pin 7, on its upper edge, is eXtend-ed from one of its corners and the said extension is formed on its inner face with teeth 10. These teeth are designed to be engaged by a cog wheel 11 on a shaft 12. The ends of the shaft are provided with cross sec- KEY. 1

Serial No. 722,319.

tionally rounded enlargements 13 and 14L re spectively, the shorter enlargement 13 being received in the pin portion or end of the stem 1, the second enlargement 14 being elongated and having formed on its end a shaft- 15 which passes through an opening 16 at the juncture of the bow of the stem. The shaft 15 has on its outer end a milled head 17, the said head having on its inner face two spaced lugs 1S1S. The lugs are received in suitable notches on the inner wall of the bow 2.

Received in the bore 6, surrounding the shaft 15, and exerting a pressure between the terminal wall of the bore 6 and the shaft enlargement 14:, there is a spring 19.

The operation of the improvement may be briefly described as follows Should the pin be projected it cannot pass through the keyhole slot for the bolt. When the key is inserted the head 17 is grasped by the operator and is given a one-half turn. This arranges the lugs 18 in a position to be again received in the notches 20 and when in such position the pin is locked projected. lVhen projected the pin is designed to engage with a suitable tumbler in the lock casing so that the locking bolt can only be thrown when the parts are arranged as just stated.

It is, of course, to be understood that the structural features disclosed by my drawings are a delineation of a satisfactory embodiment of my invention, but of course I do not wish to be restricted to such showing as I hold myself entitled to make such changes therefrom as fairly fall within the scope of what I claim.

Having described the invention, I claim:

A key comprising a stem, a bow and a bit provided with lugs, a pin slidable through one of the lugs and having an inner rack surface, a pinion in mesh with the rack surface, a shaft therefor, enlargements on the shaft received in the bore of the stem, a shaft extension on one of said enlargements, a milled head on the outer end of the extension having inner lugs, the inner face of the bow having notches to receive said lugs therein, and spring means influencing the shaft for holding the lugs in the notches.

In testimony whereof I affix my signature.

JULIUS CSIMA 

